Risk factors for linezolid-induced thrombocytopenia in adult inpatients

High accumulation of linezolid and its major metabolite in the serum of patients with hepatic and renal dysfunction is significantly associated with thrombocytopenia and anemia

This study aims to examine the serum levels of linezolid and its metabolites (PNU-142300 and PNU-142586) in patients with varying hepatic and renal function. It seeks to understand how these levels relate to thrombocytopenia and anemia and to identify concentration thresholds that could cause these adverse effects, thereby aiding in personalized drug dosing. This prospective study was conducted from January to December 2023. According to the established inclusion and exclusion criteria, 77 patients with infections treated with linezolid were selected as the research subjects. Venous blood samples were collected every 48 h starting from the first use of linezolid, specifically 30 min before the next dose. Laboratory data were obtained through biochemical analysis and blood routine tests, and blood drug concentration monitoring was carried out based on the pre-established high-performance liquid chromatography (HPLC) method. The exposure levels of linezolid and its metabolites in the serum of patients under different liver and kidney function states were compared, and the relationships between these drug exposure levels and platelet count and hemoglobin concentration were analyzed. Additionally, the receiver operating characteristic (ROC) curve was used to determine the blood drug concentration thresholds of linezolid and its metabolites that led to thrombocytopenia or anemia. Finally, survival analysis was used to evaluate the time differences in the occurrence of adverse reactions, such as thrombocytopenia and anemia, between the liver and kidney function impairment group and the normal group after the use of linezolid. Exposure to linezolid and its metabolites increased with the severity of hepatic and renal impairment. Patients with severe and moderate hepatic and renal impairment had a substantially higher median Cmin of linezolid and its metabolites 2 and 3 than those with mild hepatic and renal impairment. The platelet count and hemoglobin concentration were significantly associated with linezolid and its metabolite overexposure. The concentration threshold for linezolid and its metabolites 2 and 3 to cause thrombocytopenia and anemia were 7.0, 3.6, and 4.3 mg/L. Patients with hepatic and renal impairment exhibit higher levels of linezolid and its metabolites, potentially leading to adverse effects like thrombocytopenia and anemia. It is recommended to monitor drug levels and develop individualized dosage regimens.

IMPORTANCE

The accumulation of plasma linezolid and its metabolites increased with the degree of liver and kidney injury. High plasma linezolid and its metabolite accumulation is significantly associated with thrombocytopenia and anemia. Linezolid and its metabolite concentration threshold can warn the clinical prevention of hematological adverse reactions. Individual therapy guided by therapeutic drug monitoring (TDM) can improve the efficacy of linezolid and reduce toxic reactions. Patients with severe hepatic and renal dysfunction should actively monitor the blood routine and linezolid concentration and adjust the dosage in time.

Incidence and predictors of linezolid-associated thrombocytopenia in critically ill patients: nomogram development based on comprehensive screening of over 70 factors

BACKGROUND

Linezolid-associated thrombocytopenia (LAT) is a significant complication in intensive care unit (ICU) patients, increasing bleeding risk and leading to treatment discontinuation. This study aims to assess LAT incidence, identify risk and protective factors, and develop a predictive nomogram.

RESEARCH DESIGN AND METHODS

This retrospective cohort study included 422 adult ICU patients treated with linezolid. Over 70 clinical, demographic, laboratory, and therapeutic variables were analyzed. Logistic regression identified key risk and protective factors for LAT, and a nomogram was developed for risk prediction.

RESULTS

LAT occurred in 39.8% of patients. Risk factors included linezolid therapy > 10 days (OR 5.80, p < 0.01), solid organ tumor (OR 2.18, p = 0.03), hemodialysis (OR 5.12, p < 0.01), elevated lactate (OR 1.13, p = 0.03), and vasopressor use (OR 4.48, p < 0.01). Protective factors were surgery (OR 0.34, p < 0.01), IV N-acetylcysteine (OR 0.12, p < 0.01), oral N-acetylcysteine (OR 0.17, p < 0.01), higher baseline platelets (OR 0.79, p = 0.05), and acetaminophen (OR 0.42, p < 0.01). The nomogram showed strong discrimination (AUC 0.834, p < 0.001).

CONCLUSIONS

LAT is common in ICU patients and associated with adverse outcomes. Prolonged therapy, solid organ tumors, dialysis, high lactate, and vasopressor use increase risk; high platelet counts, N-acetylcysteine, and IV acetaminophen decrease risk. External validation and prospective trials are warranted.

Personalized Dosing of Linezolid to Reduce the Risk of Thrombocytopenia: A Systematic Review and Meta-Analysis

BACKGROUND

Linezolid-induced thrombocytopenia (LIT) occurs in a dose-dependent manner. There is no consensus regarding personalized dosing of linezolid in the real world. This study investigated the usefulness of personalized dosing for the potential mitigation of LIT compared with standard dosing.

METHODS

A systematic review and meta-analysis were performed using 4 medical electronic databases. Inclusion criteria were original research articles published up to October 23, 2023, whereas nonoriginal articles were excluded. Eligible participants included adults who were administered linezolid. A random-effects model was used to synthesize the results.

RESULTS

Four studies were eligible for inclusion. There were 208 patients in the personalized dosing (intervention) group and 195 patients in the standard dosing (comparison) group. The odds ratio for the intervention was 0.648 (95% confidence interval: 0.150-2.797), although significant heterogeneity was observed (I2 = 83.3%). An ad hoc analysis was performed by excluding one study with a significant bias risk in the treatment duration. The odds ratio for the intervention in the ad hoc analysis was 0.356 (95% confidence interval: 0.179-0.708) with little heterogeneity, showing a lower incidence risk of LIT.

CONCLUSIONS

Personalized dosing in linezolid therapy may mitigate the risk of LIT.

Evaluation of pharmacokinetic target attainment and hematological toxicity of linezolid in pediatric patients

BACKGROUND

Linezolid is commonly used to treat severe and/or resistant Gram-positive infections. Few studies have assessed its pharmacokinetic (PK) target attainment in pediatrics.

OBJECTIVE

To evaluate the percentage of pediatrics achieving the PK targets of linezolid with standard dosing regimens and to assess the incidence and risk factors associated with its hematologic toxicity.

METHODS

This prospective observational study included pediatric patients aged 0-14 who received linezolid for suspected or proven Gram-positive infections. Linezolid trough concentrations and the 24-h area under the curve (AUC24) were estimated, and hematologic toxicity was assessed.

RESULTS

Seventeen pediatric patients (5 neonates and 12 older pediatrics) were included. A wide variability was observed in linezolid's trough and AUC24 (ranging from 0.5 to 14.4 mg/L and from 86 to 700 mg.h/L, respectively). The median AUC24 was significantly higher in neonates than older pediatrics (436 [350-574] vs. 200 [134-272] mg,h/L, P = 0.01). Out of all patients, only 41% achieved adequate drug exposure (AUC24 160-300 mg.h/L and trough 2-7 mg/L), with 24% having subtherapeutic, and 35% having higher-than-optimal exposures. Hematological toxicity was observed in 53% of cases. Identified risk factors include treatment duration over 7 days, baseline platelet counts below 150 × 109/L, sepsis/septic shock, and concomitant use of meropenem.

CONCLUSIONS

Linezolid's standard dosing failed to achieve its PK targets in approximately half of our pediatric cohort. Our findings highlight the complex interplay between the risk factors of linezolid-associated hematological toxicity and underscore the importance of its vigilant use and monitoring, particularly in pediatrics with concomitant multiple risk factors.

Hematological adverse events associated with anti-MRSA agents: a real-world analysis based on FAERS

This study investigated the patterns of hematological adverse events related to daptomycin (DAP), tigecycline (TIG), vancomycin (VAN) and linezolid (LIN) in the FDA Adverse Event Reporting System (FAERS). Adverse event associations were analyzed through calculating reporting odds ratio (ROR), proportional reporting ratio (PRR), multiple gamma Poisson shrinkage (MGPS), and Bayesian confidence propagation neural network (BCPNN). A comprehensive descriptive analysis was also conducted considering factors such as age, gender, daily dose, cumulative dose, and time to onset. The leading hematologic adverse events were eosinophilia for daptomycin, coagulation abnormalities and thrombocytopenia for tigecycline, thrombocytopenia, neutropenia, and anemia for linezolid, and thrombocytopenia, eosinophilia, and neutropenia for vancomycin. Most of the affected patients were over 55 years old. Daily doses for the tigecycline and daptomycin groups exceeded the standard daily dose. The times to onset were 14.00 days for daptomycin (interquartile range [IQR], 4.00-21.00), 6.00 days for tigecycline (IQR, 2.00-9.00), 10.00 days for linezolid (IQR, 4.00-16.5), and 10.00 days for vancomycin (IQR,5.00-20.00). It is essential to intensify early monitoring and identification of these adverse events, especially in the context of off-label dosages and for elderly patients and individuals taking medication for over one week.

Development and validation of a risk prediction model for linezolid-induced anemia in elderly patients: a retrospective cohort study

Background

Linezolid-induced anemia (LI-AN) is a severe adverse reaction, but risk factors of the LI-AN for elderly patients have not been established.

Objectives

The objective of this study was to develop a nomogram capable of predicting LI-AN in elderly patients.

Design

This is a retrospective study to develop and validate a nomogram for anemia prediction in elderly patients treated with linezolid.

Methods

We retrospectively screened elderly patients treated with linezolid at Inner Mongolia People's Hospital from January 2020 to December 2023 and validated our findings using the MIMIC-IV 2.2 database. Anemia was defined as hemoglobin reduction to 75% of baseline value. Univariate and multivariable logistic regression models were used to identify predictors and construct the nomogram, which was evaluated using receiver operating characteristic (ROC) curve analysis, calibration plot, and decision curve analysis.

Results

A total of 231 patients were enrolled in this study. The training set comprised 151 individuals, and anemia occurred in 28 cases (18.54%). In the external validation set of 80 individuals, 26 (32.5%) were diagnosed with anemia. The predictors included duration of linezolid therapy, patient estimated glomerular filtration rate value, and sequential organ failure assessment score ⩾2. The ROC curve for the training set was 0.830 (95% CI: 0.750-0.910), while a similar ROC curve of 0.743 (95% CI: 0.621-0.865) was obtained for the validation set. The calibration curve demonstrated good correlation between predicted and observed results, indicating that this study effectively predicts risk factors associated with LI-AN in elderly patients.

Conclusion

The developed prediction model can provide valuable guidance for clinicians to prevent anemia and facilitate rational linezolid use in elderly patients.

Evaluation of the rational prescription of linezolid, the prevalence of thrombocytopenia and major drug interactions in patients with cardiovascular diseases: are there any cautions?

The present study evaluated the rational prescription of linezolid, the prevalence of thrombocytopenia, and major drug interactions in patients with cardiovascular diseases. We conducted a retrospective cross-sectional study on linezolid-treated patients at Shahid Chamran Heart Hospital in Isfahan from March 21, 2021, to March 20, 2022. Our research involved 132 patients who received linezolid. We reported 43.18% of linezolid prescriptions as irrational. Linezolid-induced thrombocytopenia is more common than previous studies, with a prevalence of 47.9%. We found a significant relationship between thrombocytopenia and the concomitant use of aspirin. The duration of treatment was identified as predicting factor for linezolid-induced thrombocytopenia. Moreover, the prevalence of interactions in the X and D categories was determined. Serotonergic and catecholamine medications were associated with 56.1% and 47.7% medication interactions, respectively. Our study found a high prevalence of linezolid-induced thrombocytopenia among patients with cardiovascular diseases. Based on this study, physicians should focus more closely on prescribing linezolid to patients with cardiovascular diseases. In addition to following rational antibiotic use, this susceptible group is also at an elevated risk of side effects (thrombocytopenia) and medication interactions.

Retrospective Analysis of Risk Factors for Cefoperazone/Sulbactam-Induced Thrombocytopenia in Adult Chinese Patients: A Six-Year Real-World Study

Background

Drug-induced thrombocytopenia is a rare adverse reaction of drug therapy and usually underdiagnosed. Cefoperazone/sulbactam is a compound preparation composed of the third generation of cephalosporin and β-lactamase inhibitor, of which thrombocytopenia is an uncommon but serious adverse reaction. However, the existing literature on cefoperazone/sulbactam-induced thrombocytopenia remains limited, and the specific risk factors associated with this adverse effect have not been thoroughly elucidated. Consequently, this study aims to investigate the clinical characteristics and identify the risk factors for thrombocytopenia in adult patients undergoing cefoperazone/sulbactam therapy.

Methods

In this retrospective study, we reviewed patients treated with cefoperazone/sulbactam at Beijing Hospital between January 2017 and June 2023. Patients were categorized into two groups based on the presence or absence of thrombocytopenia: the thrombocytopenia group and the non-thrombocytopenia group. We collected data on demographic features, clinical characteristics, laboratory parameters, treatments, and outcomes. Subsequently, univariate and multivariate logistic regression analyses were performed to identify potential risk factors for cefoperazone/sulbactam-induced thrombocytopenia.

Results

In total, 6489 patients were included in this study, and 2.4% (155/6489) developed thrombocytopenia. The results of multivariate analysis showed that cefoperazone/sulbactam therapy duration (d) >14, PLT (109/L) <200, daily dose of cefoperazone/sulbactam (g) ≥6, TBil (μmoL/L) >21, AST (U/L) >35, and use of non-invasive ventilator were risk factors for cefoperazone/sulbactam-induced thrombocytopenia.

Conclusion

Despite the low incidence (2.4%), cefoperazone/sulbactam could cause serious thrombocytopenia sometimes accompanied with hemorrhage. In clinical therapy, clinicians should be vigilant in monitoring platelet count, especially for patients with risk factors of cefoperazone/sulbactam-induced thrombocytopenia.

Adverse reactions caused by high serum concentration of linezolid: Two case reports and literature review

Linezolid is a potent oxazolidinone for the treatment of various gram-positive bacterial infections. However, the drug can cause potential adverse reactions such as thrombocytopenia, hyperlactacidemia and serotonin syndrome, which warrant consideration by the medical team when planning treatment. The existing literature has reported some adverse reactions caused by linezolid, but most of these are based on clinical characteristics and simple treatment measures. Two cases of linezolid overdose resulting in thrombocytopenia, hyperlactacidemia and serotonin syndrome are presented, which were successfully managed with therapeutic drug monitoring. A dose adjustment strategy was adopted to safely and effectively mitigate linezolid-related adverse events.

Linezolid-Associated Thrombocytopenia: Assessment of Risk Factors in Patients without Hemato-Oncologic Diseases

Background: Linezolid is used for Gram-positive bacterial infections. Thrombocytopenia is one of its main adverse effects resulting from myelosuppression. Several studies have assessed risk factors that may increase the risk of this adverse effect. However, most studies included patients with hemato-oncologic diseases, which may confound such assessments. This study aimed to investigate risk factors for linezolid-associated thrombocytopenia in patients without hemato-oncologic diseases. Methods: This was a multicenter retrospective case-control study of adult patients treated with linezolid twice daily for ≥3 days. Patients with hemato-oncologic diseases, active dengue fever, active COVID-19, baseline platelet count <100 × 103/mm3, concurrent therapy with trimethoprim/sulfamethoxazole or valproic acid, and a recent platelet transfusion within 7 days were excluded. Thrombocytopenia was defined as a drop in platelet count below 100 × 103/mm3. Results: Out of 158 evaluated patients, 33 developed thrombocytopenia, indicating an incidence rate of 20.9%. Of all the risk factors assessed, creatinine clearance of <60 mL/min and bacteremia/infective endocarditis were significantly associated with linezolid-associated thrombocytopenia (adjusted odds ratios, 3.25 and 5.95; 95% CI 1.12-9.45 and 1.23-28.66; p = 0.031 and 0.026, respectively). End of therapy platelet counts were significantly lower in the cases than in the controls (79 vs. 243 × 103/mm3; p < 0.001). Similarly, the percentage of platelet count change was significantly different (-55.1% vs. -10.2%; p < 0.001). Conclusions: In our study, the incidence rate of linezolid-associated thrombocytopenia was 20.9%, and we found that patients with renal impairment and bacteremia may need close monitoring of platelet counts. Prospective studies are warranted to evaluate the potential need for renal dose adjustment.

Population pharmacokinetic rationale for intravenous contezolid acefosamil followed by oral contezolid dosage regimens

Contezolid is a novel oxazolidinone antibiotic with a promising safety profile. Oral contezolid and its intravenous (IV) prodrug contezolid acefosamil (CZA) are in development for treatment of diabetic foot and acute bacterial skin and skin structure infections (ABSSSI). The prodrug CZA is converted to active contezolid via intermediate MRX-1352. This study aimed to provide the pharmacokinetic rationale for safe, effective, and flexible dosage regimens with initial IV CZA followed by oral contezolid. We simultaneously modeled plasma concentrations from 110 healthy volunteers and 74 phase 2 patients with ABSSSI via population pharmacokinetics (using the importance sampling estimation algorithm), and optimized dosage regimens by Monte Carlo simulations. This included data on MRX-1352, contezolid, and its metabolite MRX-1320 from 66 healthy volunteers receiving intravenous CZA (150-2400 mg) for up to 28 days, and 74 patients receiving oral contezolid [800 mg every 12 h (q12h)] for 10 days. The apparent total clearance for 800 mg oral contezolid with food was 16.0 L/h (23.4% coefficient of variation) in healthy volunteers and 17.7 L/h (53.8%) in patients. CZA was rapidly converted to MRX-1352, which subsequently transformed to contezolid. The proposed dosage regimen used an IV CZA 2000 mg loading dose with 1000 mg IV CZA q12h as maintenance dose(s), followed by 800 mg oral contezolid q12h (with food). During each 24-h period, Monte Carlo simulations predicted this regimen to achieve consistent areas under the curve of 91.9 mg·h/L (range: 76.3-106 mg·h/L) under all scenarios. Thus, this regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.IMPORTANCEThis study provides the population pharmacokinetic rationale for the dosage regimen of the intravenous (IV) prodrug contezolid acefosamil (CZA) followed by oral contezolid. We developed the first integrated population model for the pharmacokinetics of the MRX-1352 intermediate prodrug, active contezolid, and its main metabolite MRX-1320 based on data from three clinical studies in healthy volunteers and phase 2 patients. The proposed regimen was predicted to reliably achieve efficacious contezolid exposures independent of timing of switch from IV CZA to oral contezolid.

Predictive Modeling of Drug-Related Adverse Events with Real-World Data: A Case Study of Linezolid Hematologic Outcomes

Electronic health records (EHRs) provide meaningful knowledge of drug-related adverse events (AEs) that are not captured in standard drug development and postmarketing surveillance. Using variables obtained from EHR data in the University of California San Francisco de-identified Clinical Data Warehouse, we aimed to evaluate the potential of machine learning to predict two hematological AEs, thrombocytopenia and anemia, in a cohort of patients treated with linezolid for 3 or more days. Features for model input were extracted at linezolid initiation (index), and outcomes were characterized from index to 14 days post-treatment. Random forest classification (RFC) was used for AE prediction, and reduced feature models were evaluated using cumulative importance (cImp) for feature selection. Grade 3+ thrombocytopenia and anemia occurred in 31% of 2,171 and 56% of 2,170 evaluable patients, respectively. Of the total 53 features, as few as 7 contributed at least 50% cImp, resulting in prediction accuracies of 70% or higher and area under the receiver operating characteristic curves of 0.886 for grade 3+ thrombocytopenia and 0.759 for grade 3+ anemia. Sensitivity analyses in strictly defined patient subgroups revealed similarly high predictive performance in full and reduced feature models. A logistic regression model with the same 50% cImp features showed similar predictive performance as RFC and good concordance with RFC probability predictions after isotonic calibration, adding interpretability. Collectively, this work demonstrates potential for machine learning prediction of AE risk in real-world patients using few variables regularly available in EHRs, which may aid in clinical decision making and/or monitoring.

The development and validation of a liquid chromatography tandem mass spectrometry method for the quantification of selinexor and its application in Chinese multiple myeloma patients

Selinexor is a nuclear exportin-1 (XPO1) inhibitor that has been approved for the treatment of multiple myeloma patients. However, sustained use of selinexor may result in some undesirable consequences. Furthermore, selinexor has moderate inter-patient variability. Herein, we developed an ultrahigh-performance liquid chromatography tandem mass spectrometry method for measuring selinexor levels in human plasma ranging from 1 to 1000 ng mL-1. Furthermore, the developed approach was validated in accordance with FDA criteria. The established approach demonstrated inter-day and intra-day precision, expressed as the relative standard deviation, of less than 8%, with accuracies of less than 6%, expressed as relative error. The results showed that the protein depletion was quite complete for selinexor extraction, with recoveries ranging from 85.89 to 108.38%. The validated method facilitates the quantitation of selinexor in multiple myeloma patients. The selinexor plasma concentration exhibits obvious inter-patient' variability after administration. Thus, it is necessary to make a personalized prescription through therapeutic drug monitoring. Furthermore, the change in platelet counts before and after selinexor treatment was shown to be related to the plasma concentration at 3 h after administration, which provides the basis for therapeutic drug monitoring sampling time points and a method for predicting the occurrence of thrombocytopenia. In conclusion, the developed method can be used for the quantification of the plasma concentration of selinexor, and it is of great significance to conduct therapeutic drug monitoring for patients taking selinexor in order to enhance therapeutic effects and prevent the occurrence of adverse reactions.

Risk factors for thrombocytopenia in patients receiving linezolid therapy: a systematic review and meta-analysis

PURPOSE

The incidence of linezolid-induced thrombocytopenia (LIT) has been reported to vary widely across studies. We performed a meta-analysis to identify the risk factors for thrombocytopenia among patients who received linezolid treatment.

METHODS

The PubMed, Embase and Cochrane Library databases were searched from inception to November 2022 to identify eligible studies. Data on the potential predictors of incidence in LIT were pooled using a random effects model. Sensitivity analyses were performed to determine the robustness of the results when significant heterogeneity was observed.

RESULTS

Forty observational studies involving 6454 patients treated with linezolid were included in the analysis. LIT was estimated to occur in 37% of patients. The following important factors were associated with the incidence of LIT: advanced age, body mass index, concurrent renal impairment or liver disease, abnormal laboratory parameters (including white blood cell count, serum creatinine, baseline platelet count, albumin, creatinine clearance rate, and estimated glomerular filtration rate), treatment duration and renal replacement therapy.

CONCLUSIONS

A variety of risk factors related to the occurrence of LIT were revealed in our analysis. Early identification of these factors could help patients improve clinical outcomes.

Hematological toxicities associated with linezolid therapy in adults: key findings and clinical considerations

INTRODUCTION

Linezolid can cause serious adverse effects including thrombocytopenia and anemia. Here, we focus specifically on linezolid-related hematological toxicity in adult patients requiring prolonged drug treatment.

AREAS COVERED

We review the available evidence on the likelihood of hematological toxicity in adult patients treated with linezolid, with a focus on the main risk factors and strategies to prevent this adverse event. A MEDLINE PubMed search for articles published from January 2000 to May 2022 was completed matching the terms linezolid, hematology, hematological toxicity, anemia, and thrombocytopenia. Moreover, additional studies were identified from the reference lists of retrieved articles.

EXPERT OPINION

Thrombocytopenia is the major concern with administration of linezolid for Gram-positive infections, whereas anemia is more common in patients with tuberculosis. The important clinical risk factors for the development of linezolid-related thrombocytopenia are aging, renal dysfunction, low baseline platelet count, duration of treatment, and linezolid plasma trough concentrations >8 mg/L. Patients receiving linezolid for extended periods of time or patient populations with increased risk of altered drug pharmacokinetics would benefit from therapeutic drug monitoring or from the availability of toxico-dynamic predictive models to optimize linezolid dosing.

Safety of linezolid in patients with decreased renal function and trough monitoring: a systematic review and meta-analysis

BACKGROUND

Linezolid causes hematological toxicity, mostly thrombocytopenia, which leads to treatment discontinuation and failure. Recent studies revealed that during linezolid therapy, the incidence of treatment-related hematological toxicity is significantly higher in patients with decreased renal function (DRF) than in those with normal renal function. Linezolid monitoring is necessary due to the high frequency of hematological toxicity in patients with DRF and the relationship between blood concentration and safety. We performed a systematic review and meta-analysis to evaluate the safety correlation between DRF and trough monitoring.

METHODS

Articles published before June 24, 2022, on MEDLINE, Web of Sciences, Cochrane Register of Controlled Trials, and ClinicalTrials.gov were systematically analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method and the variable effects model.

RESULTS

The incidence of hematological toxicity was significantly higher in patients with DRF than in those without DRF (OR = 2.37; p < 0.001). Subgroup analysis, performed according to hematotoxicity classification, including thrombocytopenia, anemia, and pancytopenia, revealed a significantly higher incidence of thrombocytopenia (OR = 2.45; p < 0.001) and anemia (OR = 2.31; p = 0.006) in patients with DRF than in those without; pancytopenia (OR = 1.41; p = 0.80) incidences were not significantly higher. Based on a systematic review, linezolid trough concentrations > 6-7 μg/mL may be associated with an increased incidence of thrombocytopenia. However, no confidential threshold values for the development of thrombocytopenia were found in the area under the concentration curve values for children or adults.

CONCLUSION

We observed a high frequency of hematological toxicity during linezolid therapy in patients with DRF. To ensure safety, linezolid trough concentrations should be ≤6-7 μg/mL.

Identifying and Targeting Prediction of the PI3K-AKT Signaling Pathway in Drug-Induced Thrombocytopenia in Infected Patients Receiving Linezolid Therapy: A Network Pharmacology-Based Analysis

The pharmacological mechanisms underlying the adverse effects of linezolid on thrombocytopenia have not been conclusively determined. This network pharmacology study aimed at investigating the potential pharmacological mechanisms of linezolid-induced adverse reactions in thrombocytopenia. In this study, target genes for linezolid and thrombocytopenia were compared and analyzed. Overlapping thrombocytopenia-associated targets and predicted targets of linezolid were imported to establish protein-protein interaction networks. Gene Ontology and the Kyoto Encyclopedia of Genes and Genome pathway enrichment analyses were performed to determine the enriched biological terms and pathways. The mechanisms involved in linezolid-induced thrombocytopenia were established to be associated with various biological processes, including T cell activation, peptidyl serine modification, and peptidyl serine phosphorylation. The top five relevant protein targets were obtained, including ALB, AKT1, EGFR, IL6, and MTOR. Enrichment analysis showed that the targets of linezolid were positively correlated with T cell activation responses. The mechanism of action of linezolid was positively correlated with the PI3K-AKT signaling pathway and negatively correlated with the Ras signaling pathway. We identified the important protein targets and signaling pathways involved in linezolid-induced thrombocytopenia in anti-infection therapy, providing new information for subsequent studies on the pathogenesis of drug-induced thrombocytopenia and potential therapeutic strategies for rational use of linezolid in clinical settings.

Relationship Between Linezolid Exposure and the Typical Clinical Laboratory Safety and Bacterial Clearance in Chinese Pediatric Patients

Objectives: There have been limited studies concerning the safety and efficacy of linezolid (LZD) in children. This study aimed to evaluate the association between LZD exposure and clinical safety and efficacy in Chinese pediatric patients.

Methods: This retrospective cross-sectional study included patients ≤18 years of age who received ≥3 days of LZD treatment between 31 January 2015, and 31 December 2020. Demographic characteristics, medication information, laboratory test information, and bacterial culture results were collected from the Hospital Information System (HIS). Exposure was defined as AUC₂₄ and calculated by the non-linear mixed-effects modeling program (NONMEM), version 7.2, based on two validated population pharmacokinetic models. Binary logistic regression analyses were performed to analyze the associations between AUC₂₄ and laboratory adverse events, and receiver operating characteristic curves were used to calculate the cut-off values. Efficacy was evaluated by bacterial clearance.

Results: A total of 413 paediatric patients were included, with an LZD median (interquartile range) dose, duration, clearance and AUC₂₄ of 30.0 (28.1-31.6) mg/kg/day, 8 (4‒15) days,1.31 (1.29-1.32) L/h and 81.1 (60.6-108.7) mg/L·h, respectively. Adverse events associated with TBil, AST, ALT, PLT, hemoglobin, WBC, and neutrophil count increased during and after LZD treatment when compared with before medication (p < 0.05), and the most common adverse events were thrombocytopaenia (71/399, 17.8%) and low hemoglobin (61/401, 15.2%) during the LZD treatment. Patients with AUC₂₄ higher than 120.69 mg/L h might be associated with low hemoglobin 1–7 days after the end of the LZD treatment, and those with an AUC₂₄ higher than 92.88 mg/L∙h might be associated with thrombocytopaenia 8–15 days after the end of the LZD treatment. A total of 136 patients underwent bacterial culture both before and after LZD treatment, and the infection was cleared in 92.6% (126/136) of the patients, of whom 69.8% (88/126) had AUC₂₄/MIC values greater than 80.

Conclusion: Hematological indicators should be carefully monitored during LZD treatment, especially thrombocytopaenia and low hemoglobin, and a continuous period of monitoring after LZD withdrawal is also necessary. Since the AUC₂₄ cut-off values for laboratory adverse events were relatively low, a trade-off is necessary between the level of drug exposure required for treatment and safety, and the exposure target (AUC₂₄/MIC) in pediatric patients should be further studied, especially for patients with complications and concomitant medications.